Some of the suppliers I've used in the past (mostly American!)Jas Townsend and Son
Warning: This site is addictive - you will want to buy EVERYTHING. They're very good with their delivery times and stuff, too.G Gedney Godwin
Not quite as extensive a collection as Jas Townsend, but still interesting. I've not actually bought anything from them, so I don't know what they're like with deliveries, problems etc.
Patterns and fabrics suppliers:Kannick's Korner
Easy-to-follow patterns for a wide variety of thingsPatterns of Time
If they haven't got it... it probably isn't worth having!Wm Booth, Draper
A decent selection of period fabricsPeriod Fabric
Again, a decent selection, though the website isn't completely up to date.Ticking
If you're like me and need ticking, this looks like a good place to get it - they have it in a variety of different colours, too. A little pricey, though.